In general, a disk drive, such as a hard disk drive (HDD), comprises a magnetic disk, spindle motor, magnetic head, carriage assembly, voice coil motor, board unit, etc. The spindle motor serves to rotate the magnetic disk. The magnetic head reads data from and writes data to the magnetic disk. The carriage assembly supports the magnetic head. The voice coil motor serves to drive the carriage assembly. All these components are accommodated in a substantially sealed housing.
In the HDD of this type, the number of rotation of the magnetic disk must be increased to perform high-speed data processing. If the magnetic disk rotates at high speed, however, airflow is produced that rotates in the same direction as the magnetic disk, and a phenomenon called disk flutter is caused such that the magnetic disk vibrates because of disturbance of this airflow. Further, airflow disturbance acts on the carriage that supports the magnetic head, whereupon the carriage is displaced. In this case, the accuracy of positioning of the magnetic head relative to the magnetic disk is reduced, so that the recording density cannot be increased.
A magnetic disk drive is adopted in which a squeeze plate or spoiler is opposed to a surface of a magnetic disk with a small gap, in order to regulate airflow produced by high-speed rotation of the magnetic disk. This flow regulation plate is disposed so as to cover the entire opposite surfaces of the magnetic disk except movement paths for a magnetic head and arm. Another device is adopted in which a flow regulation plate or posture stabilizing member opposed to a surface of a magnetic disk with a small gap is provided covering the entire area around an arm except movement paths for a magnetic head and the arm.
Airflow disturbance acting on an actuator can be suppressed to improve the on-track accuracy by means of the squeeze plate or spoiler interposed between magnetic disk surfaces. According to this arrangement, however, the rotational loss of the magnetic disk is increased, so that the motor power consumption is increased. In view of the recent development of improved energy-saving technologies, high recording density should be achieved without increasing in energy consumption.